refact(breaking): removed type PanicTestFunc and replaced it by just func() (#46)

Signed-off-by: Frederic BIDON <fredbi@yahoo.com>

Author: fredbi

assert/assert_adhoc_example_5_test.go

@@ -26,7 +26,7 @@ func ExamplePanicAssertionFunc() {
 
 type panicAssertionCase struct {
 	name      string
-	panicFn   assert.PanicTestFunc
+	panicFn   func()
 	assertion assert.PanicAssertionFunc
 }